1. User Management APIs

These APIs allow for user authentication, registration, profile management, and user preferences.

A. User Authentication API

Login API: Allows users to authenticate and log into Messenger using credentials (username/password, OAuth, or social media login like Facebook or Google).

• Example Endpoint: POST /login
• Request: { "username": "john_doe", "password": "password123" }
• Response: { "token": "jwt_token" }

Logout API: Logs the user out and invalidates the session.

• Example Endpoint: POST /logout
• Response: { "status": "success" }

B. User Registration API

Sign-Up API: Allows a new user to register and create an account on Messenger by providing necessary details.

• Example Endpoint: POST /register
• Request: { "email": "[email protected]", "password": "password123", "name": "John Doe" }
• Response: { "status": "user_created", "user_id": "12345" }

C. Profile Management API

Update Profile API: Allows users to update their profile information such as name, profile picture, and status.

• Example Endpoint: PUT /user/{user_id}/profile
• Request: { "name": "John", "profile_pic": "image_url" }
• Response: { "status": "profile_updated" }

2. Message Management APIs

These APIs manage the core functionality of text, voice, and video messaging.

A. Send Message API

Send Text Message API: This API allows users to send a text message to one or more recipients.

• Example Endpoint: POST /message/send
• Request: { "sender_id": "12345", "receiver_id": "67890", "message": "Hello, how are you?" }
• Response: { "status": "message_sent", "message_id": "abc123" }

B. Media Message API

Send Media Message API: This API allows users to send photos, videos, and voice notes as part of their message.

• Example Endpoint: POST /message/send_media
• Request: { "sender_id": "12345", "receiver_id": "67890", "media_type": "image", "media_url": "image_url" }
• Response: { "status": "media_sent", "message_id": "xyz456" }

C. Retrieve Message History API

Fetch Message API: This API allows users to fetch the message history from a particular conversation.

• Example Endpoint: GET /message/history
• Request: { "conversation_id": "chat123", "limit": 20 }
• Response: [ { "message_id": "abc123", "sender_id": "12345", "text": "Hello, how are you?" }, ... ]

D. Delete Message API

Delete Message API: This allows a user to delete a specific message from a conversation.

• Example Endpoint: DELETE /message/{message_id}
• Request: { "message_id": "abc123" }
• Response: { "status": "message_deleted" }

3. Real-Time Communication APIs

These APIs enable real-time messaging, voice, and video calling, which are the core features of Messenger.

A. WebSocket for Real-Time Messaging

WebSocket API: Messenger uses WebSockets for real-time communication, allowing instant delivery of messages and notifications.

• Example Endpoint: ws://messenger.com/socket
• Usage: This API enables the server to push notifications and new messages to the client immediately after they are sent, without the need to refresh or poll for updates.

B. Voice Call API

Initiate Voice Call API: This API allows users to initiate a voice call with another user.

• Example Endpoint: POST /call/voice/initiate
• Request: { "caller_id": "12345", "receiver_id": "67890" }
• Response: { "status": "call_initiated", "call_id": "call123" }

Answer Voice Call API: This API lets the user answer an incoming voice call.

• Example Endpoint: POST /call/voice/answer
• Request: { "call_id": "call123", "answer": true }
• Response: { "status": "call_accepted" }

C. Video Call API

Initiate Video Call API: Similar to the voice call API, but for video calls. It allows users to start a video chat with another user.

• Example Endpoint: POST /call/video/initiate
• Request: { "caller_id": "12345", "receiver_id": "67890" }
• Response: { "status": "video_call_initiated", "call_id": "video123" }

Answer Video Call API: This API is used to accept an incoming video call.

• Example Endpoint: POST /call/video/answer
• Request: { "call_id": "video123", "answer": true }
• Response: { "status": "video_call_accepted" }

4. Notification Management APIs

These APIs are used to send notifications to users, ensuring they are alerted about new messages, calls, or events.

A. Push Notification API

Send Push Notification API: Sends push notifications to a user’s device when a new message or event occurs.

• Example Endpoint: POST /notification/push
• Request: { "user_id": "12345", "message": "You have a new message!" }
• Response: { "status": "notification_sent" }

B. Email Notification API

Send Email Notification API: Sends an email to the user for certain events, such as a password reset or security alerts.

• Example Endpoint: POST /notification/email
• Request: { "user_email": "[email protected]", "subject": "Password Reset", "body": "Click here to reset your password" }
• Response: { "status": "email_sent" }

5. Group and Chat Management APIs

These APIs are used for creating and managing group chats and conversations.

A. Create Group API

Create Group Chat API: This API allows users to create a group chat with multiple participants.

• Example Endpoint: POST /group/create
• Request: { "group_name": "Family Chat", "participants": ["12345", "67890", "11223"] }
• Response: { "status": "group_created", "group_id": "group123" }

B. Add/Remove Participants API

Add Participant API: This API allows users to add a new participant to an existing group.

• Example Endpoint: POST /group/{group_id}/add
• Request: { "user_id": "33445" }
• Response: { "status": "participant_added" }

Remove Participant API: This API allows users to remove a participant from a group.

• Example Endpoint: POST /group/{group_id}/remove
• Request: { "user_id": "67890" }
• Response: { "status": "participant_removed" }

6. Analytics and Usage Tracking APIs

These APIs are used to track usage patterns, message volume, active users, and performance metrics.

A. Message Statistics API

Fetch Message Stats API: This API provides statistics such as the number of messages sent, active users, etc., over a given period.

• Example Endpoint: GET /stats/messages
• Request: { "start_date": "2025-01-01", "end_date": "2025-01-31" }
• Response: { "messages_sent": 5000000, "active_users": 1000000 }

B. System Health and Metrics API

Fetch System Metrics API: This API provides health data, such as server load, memory usage, and response times.

• Example Endpoint: GET /system/health
• Response: { "cpu_usage": "70%", "memory_usage": "65%" }